Perovskite materials have sparked great excitement in optoelectronics in last two decades due to
their low-cost and high-performance in devices. The devices include solar cells (SCs), light-emitting
diodes (LEDs), photodetectors, X‐ ray detectors, lasers and memristors. Generally,
perovskite structures can be synthesized in a variety of forms such as bulk material, two-dimensional
materials, and colloidal quantum dots (QDs). Bulk perovskite materials have shown
tremendous progress in SCs, achieving remarkable power conversion efficiencies (PCEs). On the
other side, perovskite QDs have become the new paradigm for LEDs due to their high
photoluminescence quantum yield (PLQY) and tunable emission wavelength. By employing
perovskites as an active layer of the LED or SCs, high-performance fu...[
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Perovskite materials have sparked great excitement in optoelectronics in last two decades due to
their low-cost and high-performance in devices. The devices include solar cells (SCs), light-emitting
diodes (LEDs), photodetectors, X‐ ray detectors, lasers and memristors. Generally,
perovskite structures can be synthesized in a variety of forms such as bulk material, two-dimensional
materials, and colloidal quantum dots (QDs). Bulk perovskite materials have shown
tremendous progress in SCs, achieving remarkable power conversion efficiencies (PCEs). On the
other side, perovskite QDs have become the new paradigm for LEDs due to their high
photoluminescence quantum yield (PLQY) and tunable emission wavelength. By employing
perovskites as an active layer of the LED or SCs, high-performance functional devices can be
fabricated. This is due to their unique features such as ease of synthesis, size control, and
composition tunability of the bandgap and confined excitons. In this research, we investigate
perovskite synthesis, solvent chemistry, and its impact on device performances.
The research is divided into three parts. At first, we focus on the perovskite QDs synthesis,
optoelectronic properties, their application in SCs. The current state of the art of QDs, problems
associated with ligand chemistry, is briefly investigated. Perovskite QD devices still deteriorate
from fabrication issues such as poor surface morphology, surface defects, and notably insulating
native lands such as anionic oleate and cationic oleylammonium ligands. A novel layer-by-layer
(LBL) ligand chemistry has been developed to overcome the problems. As a result, QDSC was
fabricated in p–i–n inverted configurations. The efficiency was improved from 11.50 % for the
control to 13.1 % for the new ligand chemistry devices.
In the second part, solvent engineering of formamidinium lead bromide (FAPbBr
3) perovskites
have been investigated. The one-step fabrication of FAPbBr
3 perovskites has not been thoroughly
investigated. Particularly, solvent‐dependent crystallization, the chemical transformation route to
FAPbBr
3, and the crystalline intermediates of FA‐based perovskites. Herein, a new protocol using
a one‐step deposition method for producing formamidinium lead bromide (FAPbBr
3) perovskites
are reported, which features a solvent‐engineered intermediate phase to achieve superior films. As
a result, inverted SCs using solvent engineered films achieve power conversion efficiencies (PCEs)
of up to 9.06 %, the highest reported efficiency for inverted FAPbBr
3 perovskite devices.
The third part focuses on fabricating semitransparent perovskite SCs (STPSCs) based on FAPbBr
3
perovskites. We varied the perovskite precursors concentrations and optimized the antisolvent
strategy to achieve high-quality pin-hole free films. The semitransparent devices with different
concentrations such as C1 (1.2 M), C2 (0.8 M), C3 (0.4 M) obtained the average visible
transmittance of 35.6 %, 42.5 % and 49.2 %, respectively. The device results are presented with
future directions.
The last project is carried out to find the solution for the stability of iodide-based perovskite. We
have identified the polymer PCF, which improves the stability and photoluminescence of MAPbI
3
perovskites. The passivation of defects using PCF has been thoroughly investigated. The PCF
structural properties and crystallization effects on MAPbI
3 grains have been studied. Near-infrared
LED has been constructed based on utilizing an optimized concentration of PCF polymer.
Collectively, this research includes the synthesis of inorganic MHPs nanostructures, ligand
chemistry for efficient devices, solvent engineering in wideband gap FAPbBr
3 perovskites. The
projects utilized various in-depth scientific characterizations on pursuing the fundamental
understanding of the synthesis, material properties and fabrication of efficient devices.
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